General Chemistry

Introduction to Acid-Base Reactions

September 19, 2011

Following up on the 4 major classes of reactions you encounter in Org 1, let’s look at the first of those four: acid base reactions. The focus here is not initially to understand why things happen the way they do – that comes later. The initial focus is to be able to recognize what is happening. Just [...]

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Calculating the oxidation state of a carbon

July 25, 2011

Try applying the rules for calculating oxidation states to carbon.

It’s going to feel a little bit weird. Why? Because there are two key differences.

First, carbon is often more electronegative (2.5) than some of the atoms it’s bound to (such as H, 2.2). So what do you do in this case?
Secondly, unlike metal-metal bonds, carbon-carbon bonds are ubiquitous. So how do you deal with them?

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Org 1 Review Quizzes

January 7, 2011

This past semester after every tutorial session I would send an email to my student with a list of topics that we discussed, and then a list of questions intended to stimulate thinking about the key concepts we talked about. I still do this: I think it’s helpful for both me and the student to [...]

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What’s a Transition State?

November 3, 2010

Here’s a question that comes up a lot: What’s a transition state? In the Harry Potter series, Remus Lupin changed to his werewolf form when the moon was full. But he didn’t go from human to werewolf just by snapping his fingers:  the fangs and hair had to grow, the spine curled, the hands became [...]

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3 Trends That Affect Boiling Points

October 25, 2010

Figuring out the order of boiling points is all about understanding trends. The key thing to consider here is that boiling points reflect the strength of forces between molecules. The more they stick together, the more energy it will take to blast them into the atmosphere as gases. There are 3 important trends to consider. [...]

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Meet the (Most Important) Functional Groups

October 6, 2010

Functional groups are specific groups of atoms within molecules that have very characteristic properties regardless of the other atoms present in a molecule. You’re probably familiar with several of them by now – alcohols, amines, carboxylic acids, ketones, and ethers are all common examples. How many functional groups are there? Depending on how fine you [...]

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The Four Intermolecular Forces and How They Affect Boiling Points

October 1, 2010

It’s amazing how much chemistry comes down to simple attraction between opposite charges and repulsion between like charges. This is the driving force behind chemical bonding, of course. But it’s also responsible for the forces between molecules. This means that properties like melting and boiling points are a measure of how strong the attractive forces [...]

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How to Use a pKa Table

September 29, 2010

Today we’ll talk about an incredibly important skill that might take some time to grasp but pays tremendous dividends. We’ll go through the exact details of how to use a pKa table. Understanding the proper use of a pKa table will give you the ability to recognize which acid-base reactions will happen and which will not. This will come up a lot as you progress through Org 1 and Org 2. It might be helpful to go back and review some of the factors that affect acidity that were talked about earlier.

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From Gen Chem to Organic Chem, Part 14: Wrapup

September 15, 2010

So what are the key concepts from General Chemistry that you need to apply to Organic Chemistry, going in? This past summer, I saw people asking this question on places like Yahoo Answers and SDN all the time. So I decided to do something about it. It was embarrassing how much 1st year chemistry I’d [...]

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From Gen Chem to Organic Chem, Pt. 13 – Equilibria

September 13, 2010

(The last lesson in the series. I wish I had this series done by the time school started for most people, but I initially thought I could cover the basics of Gen Chem in 6 posts and it just kept growing – planning fallacy in action.) Chemical Equilibria In chemistry, irreversible reactions get all the [...]

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